Fitment question

Hey everyone I just bought two new continental tkc80 twinduro. My question is that the twinduros are a size 3.50/18 and my original rear tire is a 120/80-18 the salesman said they'll fit fine but it will just be a bit narrower, is that right? He also didn't have an exact size tube for the rear but he sold me a an sti heavy duty tube size 110/100-18 to 120/100-18.
So basically long story short will that tube, in a 3.50 size tire work fine on my 2.15/18 rim that has an oem tire size of 120/80-18 aside from the tire being a bit narrower?

All this time I thought I was the only person who would buy shit and then later ask the question "Gee, I wonder if that will work?"

I think you will be fine. Hard to tell from the tire sizes since the manufacturers don't always measure their tires the same way. If anything I think the tire will be a little smaller than a 120/80. You should be ok with the tube too. I have ran a 140/80 tube on a 120/80 tire before. Just need to be careful of pinching the tube when installing the tire.

Normally the dealer should sell you what you need and not what will work. Shouldn't be a big deal for him to order the right stuff and if they don't want to do that they should give you a decent price on the other stuff.

Today there are so many other ways to get what you need. Motorcycle Superstore and Rocky Mountain ATC/MC online stores generally will have what you need and in stock. Once you are over usually $80 or $100 the shipping is free. Dealers need to focus on Customer Service and getting you what you need if they want to stay in business.

Thanks for the quick reply, I was going to buy a set of Dunlop 606's which would be a bit bigger so I figured going a bit smaller wouldn't hurt much either. I got these tkc80s instead because they were on close out for only $39 each! So I got the last two they had. My main concern was the tube though and the dealer is 70 miles away so thanks for putting my mid at ease. I was prepared to buy off Rocky Mountain or revzilla but I like the instant gratification haha and you can't beat that price

$39 each sounds like a good deal on tires.. you're into Shinko 244 territory on that price!

Yea, and I figure they'll be better on the snow compared to the stock size since narrower tires bite better? At least that's the case with cars

Yes a Continental TKC80, size 3.50 will fit on the rear rim with some effort but the tube that I mentioned was too big and I ended up pinching it, went to a different dealer and got an oem tube. Tire feels great on hard surfaces and even though it is narrower it still performs better than the stock trailwing on mud, running a new 301 trailwing upfront